Answer:
Biker will catch the cyclist after 2 hr and 40 min.
Step-by-step explanation:
Given:
Speed of Bicyclist = 20 km/h
Travelling time = 4 hrs
∴ Distance = Speed × Time =
Also he rest for 1 hr.
So we can say that, after 5 hrs Bicyclist is 80 km ahead when the biker Started.
Now Biker rate is given 50 km/h
And Bicyclist rate is 20 km/h
So, for each hour, biker advances 50 - 20 = 30 kilometers
now bicyclist distance is 80 km
and biker advances 30 per hour.
Therefore to catch up bicyclist at 80 km i.e time taken to reach 80 km with 30 km rate per hour.
Time =
Hence, Biker will catch the cyclist after 2 hr and 40 min.